Decay Model

The decay model is a statistical approach that measures how the impact of stressful life events on bipolar mood episodes diminishes over time. It suggests while life events (loss of a loved one or severe personal crisis) increase the risk of triggering mania or depression, their impact is not permanent — and weakens as more time passes from the event. Here are key components in the decay model in bipolar disorder:

• 25% annual decay rate, according to research, best explains the relationship between life events and BD hospital admission rates.
• Context within the kindling hypothesis which suggests early BD episodes are often triggered by stressful life events, but later episodes become more autonomous and less dependent on external stressors.
• Cumulative life event load (total stress), as the model calculates, applies a penalty to older events, recognizing that an event that occurred 5 years ago has less impact on a current episode than an event that happened last month.
• Reduction in impact over time is thought to be related to coping strategies, personal resilience, and behavioral adaptations, reducing sensitivity to past stressors